1. Field of the Invention
The present invention is directed to a mount apparatus for mounting a measurement device on a rail car. In particular, the present invention is directed to a mount apparatus that is movably secured to a rail car which maintains a substantially fixed vertical position relative to the track surface of a railroad track.
2. Description of Related Art
Various types of rail cars with different types of axle suspension systems are known and used in the railroad transportation industry for rail cars of freight and passenger trains. Axle suspension systems serve an important function in that they suspend and stabilize the rail cars by allowing the wheels of the rail cars to move relative to the frame of the rail car body. Thus, the axle suspension systems allow wheels of the rail car to absorb impact which occurs as the wheels roll along the track surface of the railroad track. The axle suspension systems also allow isolation of the rail car to provide a more comfortable ride to passengers of passenger rail cars having axle suspension systems.
Generally axle suspension systems include trucks having axles with wheels attached thereto. The axles are typically mounted to the truck via axle bearing housings, suspension links which locate the axle bearing housings, and springs which suspends the truck over the axles. The rail car body is secured over the truck, with or without other suspension components between the rail car body and the frame of the truck. Thus, the wheels, the axles, and the axle bearing housings are unsprung components of the axle suspension system whereas the truck frame of the axle suspension component is a sprung component.
U.S. Pat. No. 4,356,775 to Paton et al. shows one example of a dampened railway car suspension including a movable load arm assembly for supporting a rail car axle. The load arm assembly to which the axle is attached is movable relative to the truck and thus, is movable relative to the rail car itself. Such movable load arm assemblies allow use of springs and dampeners to absorb impact which occurs as the wheels roll along the track surface of the railroad track. By providing such suspension, the wheels of the rail cars are better controlled and the ride quality of the rail cars is improved as previously noted.
U.S. Pat. No. 5,001,989 to Mulcahy et al. shows another example of a single axle suspension system for rail car truck. Mulcahy et al. discloses a single axle railway truck having an axle box with spring support for suspending the frame of the rail car. The suspension system disclosed in Mulcahy et al. also includes a lateral traction rod which is supported by the single axle and secured to the side frame of the rail car, the lateral traction rod being a component of the suspension system.
Further, rail condition is a very important aspect of rail transit safety. Any damage or defects in the track surface, the railroad track alignment, and other rail parameters can cause derailment of the rail car which will result in significant property damage and possible injury to the train operators, passengers, and bystanders. Consequently, continual inspections are made to ensure that the railroad tracks are in good condition so that chances of derailment are minimized.
In the above regard, measurement devices such as electronic sensors and other mechanical/electro-mechanical devices are now being used in various ways to monitor the condition of the railroad tracks and the track surface. Such sensors and other measurement devices utilize laser, optical, magnetic, or other mechanical/electromechanical technologies to measure various parameters of the track surface and alignment of the railroad track so that the condition of the track surface and the railroad track can be monitored.